First, the mechanical seal requirements on machine accuracy: (Take the vacuum pump mechanical seal as an example)

(1) The radial runout tolerance of the shaft (or shaft sleeve) where the mechanical seal is installed does not exceed 0.04 to 0.06 mm.

(2) The axial movement of the rotor does not exceed 0.3 mm.

(3) The runout tolerance of the positioning end of the sealing cavity combined with the sealing end cap on the surface of the shaft (or sleeve) does not exceed 0.04 to 0.06mm.

2. Confirmation of seals:

(1) Confirm whether the installed seal is consistent with the required model.

(2) Before installation, carefully compare with the assembly drawing to see if the number of parts is complete.

(3) The mechanical seal is driven by parallel coil springs, the springs are divided into left and right, and must be selected according to the rotation direction of the rotating shaft.

3. Installation method of seals:

The installation method varies with the type of mechanical seal and the type of machine, but the installation methods are almost the same. The installation steps and precautions are as follows:

(1) Determination of installation size: During installation, the installation size of the mechanical seal should be ensured according to the instruction manual or sample of the product.

(2) Before loading, the shaft (sleeve) and the gland should be free of burrs, and the bearing should be in good condition; the seals, shaft, seal cavity, and gland should be cleaned. In order to reduce friction resistance, a thin layer of oil should be applied to the part of the shaft where the mechanical seal is installed for lubrication. Considering the compatibility of the rubber O-ring, if oil is not suitable, soapy water can be applied. The floating static ring has no anti-rotation pin structure and should not be oiled. It should be installed dry into the gland.

(3) First install the static ring and the gland on the shaft, taking care not to touch the shaft, and then install the moving ring assembly. The set screw of the spring seat or transmission seat should be tightened evenly in several times.

Before fixing the gland, push the compensation ring by hand for axial compression. After loosening, the compensation ring can automatically spring back without jamming, and then the gland bolts are evenly locked.